The React Health G3 X reads your breathing and adjusts your pressure all night, so therapy stays comfortable enough to actually stick with. Its heated humidifier and tubing are built in for warm, easy air, and it runs quietly enough not to bother your partner.The Nova Micro is about as light as a mask gets. It rests gently at your nostrils, barely touches your face, and keeps your line of sight open, which helps if other masks have felt bulky or closed-in. It uses no magnets, so it's safe with a pacemaker or other implant.